The present invention, in some embodiments thereof, relates to laboratory equipment and, more particularly, but not exclusively, to pipettes and methods of manufacturing thereof.
Pipettes, slender tubes used in laboratories to measure and transfer fluids, usually have cone-shaped hollow open tips which allow acquiring, transporting, and dispensing fluid samples. In use, at least the lower end of the pipette tip is placed in contact with a liquid to be sampled. The pipette is then operated to draw air from inside the pipette tip at the upper end, and the resultant suction draws the sampled liquid into the pipette tip. Air pressure maintains the liquid inside the pipette tip until the pipette is operated to release the liquid, generally by expelling the drawn air.
Improvements to pipettes and the respective manufacturing processes have been developed during the last years.
For example, U.S. Pat. No. 7,794,664 describes a pipette tip which includes a main body having an upper end, a lower end and a sidewall extending between the two ends. A bore extends axially through the main body between the upper and lower ends. The lower end has a bottom surface in which is formed a central opening that communicates with the axial bore to allow the passage of fluid therethrough. The bottom surface is formed with at least one groove that may be concentrically disposed or spirally disposed about the central opening. The at least one groove acts to inhibit fluid passing through the central opening from at least partially flowing along the outer surface of the sidewall from the central opening toward the upper end of the main body of the pipette tip.
Another example is provided in U.S. Pat. No. 6,280,689 which describes pipette for dispensing a fluid medium into an open-ended collection container including an improved dripless tip. The pipette includes a tip body with a cross shaped passage structure that spans the length of the tip body. This cross shaped passage structure is designed to contact the liquid medium that passes into the tip and onto the open distal end of the tip and prevent unwanted dripping therefrom.